概括
来自康科德超音速运输的声波爆发揭示了大气条件. 超声波信号提供了来自平流层和热层层次的温度和风数据.
科学领域:
- 大气科学 大气科学
- 声学 声学 在声学方面
- 地质物理学 地质物理学
背景情况:
- 超音速飞机产生的超声波可以远距离传播.
- 大气条件显著影响声波的传播和特征.
研究的目的:
- 为了分析来自康科德飞机的超声波波的超声波信号.
- 研究信号频率与大气反射水平之间的关系.
- 为了确定声波波是否可以用于导出大气温度和风参数.
主要方法:
- 记录来自康科德飞机的超声波冲动在纽约帕利萨德斯的声波爆发.
- 分析由于平流层和热层高度的温度和风条件导致的信号折射.
- 与大气反射水平和声速相关联的信号频率.
主要成果:
- 从高达1000公里的距离记录了超声波信号.
- 发现信号频率取决于反射高度,随着大气稀释而下降.
- 水平的轨迹速度与反射水平的声速相匹配.
- 每日信号变化表明大气参数的显著波动.
结论:
- 康科德的声波波会产生超声波,可以用来探测上层大气层.
- 信号的频率和速度提供了关于平流层和热层层温度和风的数据.
- 观察到的每日变化凸显了这些大气参数的动态性质.
相关概念视频
Shock Waves
While deriving the Doppler formula for the observed frequency of a sound wave, it is assumed that the speed of sound in the medium is greater than the source's speed through it. When this condition is breached, a shock wave occurs.
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...
Sound as Pressure Waves
Sound waves, which are longitudinal waves, can be modeled as the displacement amplitude varying as a function of the spatial and temporal coordinates. As a column of the medium is displaced, its successive columns are also displaced. As the successive displacements differ relatively, a pressure difference with the surrounding pressure is created. The gauge pressure varies across the medium.
The pressure fluctuation depends on the difference in displacements between the successive points in the...
The pressure fluctuation depends on the difference in displacements between the successive points in the...
Sound Waves: Resonance
Resonance is produced depending on the boundary conditions imposed on a wave. Resonance can be produced in a string under tension with symmetrical boundary conditions (i.e., has a node at each end). A node is defined as a fixed point where the string does not move. The symmetrical boundary conditions result in some frequencies resonating and producing standing waves, while other frequencies interfere destructively. Sound waves can resonate in a hollow tube, and the frequencies of the sound...
Sound Waves: Interference
Sound waves can be modeled either as longitudinal waves, wherein the molecules of the medium oscillate around an equilibrium position, or as pressure waves. When two identical waves from the same source superimpose on each other, the combination of two crests or two troughs results in amplitude reinforcement known as constructive interference. If two identical waves, that are initially in phase, become out of phase because of different path lengths, the combination of crests with troughs...
Intensity and Pressure of Sound Waves
The intensity of sound waves can be related to displacement and pressure amplitudes by using their wave expressions and the definition of intensity. The critical step to achieve this is to write the power delivered by the particles on the wave as the product of force and velocity and simplify the force per unit area as the pressure. The velocity of the medium's particles can be derived from the displacement.
Unlike the time average of a sinusoidal term, which is zero since it is positive and...
Unlike the time average of a sinusoidal term, which is zero since it is positive and...
Perception of Sound Waves
The human ear is not equally sensitive to all frequencies in the audible range. It may perceive sound waves with the same pressure but different frequencies as having different loudness. Moreover, the perception of sound waves depends on the health of an individual's ears, which decays with age. The health of one's ears may also be affected by regular exposure to loud noises.
The pitch of a sound depends on the frequency and the pressure amplitude of the source. Two sounds of the same frequency...
The pitch of a sound depends on the frequency and the pressure amplitude of the source. Two sounds of the same frequency...


